GLENTEK Inc. 208 Standard Street, El Segundo, California 90245, U.S.A. (310) 322-3026
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CHAPTER SIX: START UP AND ADJUSTMENT PROCEDURE
6.1 SAFETY PRECAUTIONS:
Before starting the adjustment and alignment procedure please be sure to observe the following pre-
cautions:
1. Be certain that there are no visibly loose or damaged components.
2. Check that all connections are tight.
3. Check all power and signal wiring. Remove power input fuses, apply power and measure that correct
power voltage is being applied. Your DC bus voltage will be 1.4 times the AC voltage applied (Refer to Ap-
pendix A, note 1).
4. Be sure that the motor mechanism is clear of all obstructions. If motor is connected to an axis lead screw
or other device with limited motion, place at mid position.
6. Make sure Loop-Gain potentiometer (on Preamp card) is turned fully CCW before applying power.
7.
DO NOT
use grounded test equipment on motor leads or power section of amplifier.
6.2 AMPLIFIER ALIGNMENT INTRODUCTION:
When adjusting an amplifier for optimum velocity-loop operation it is desirable to achieve a critically
damped, stable-step velocity response with maximum Tach Gain. The following discussion will describe how to
best achieve this result:
Your amplifier has been run at the factory with a known motor, tachometer and inertial load. In testing at
the factory, we try to simulate the same conditions you will have in your system. For this reason it is a good
idea to start with the initial settings as shipped from the factory.
NOTE: All of the following adjustments are to be made on the Personality Preamp card (Refer to Appendix C,
drawings 4597-7010 & 4597-7012).
6.3 VELOCITY-LOOP PHASING:
For proper servo operation it is necessary for the amplifier to receive negative feedback from the tachome-
ter. If the tachometer leads are reversed (positive feedback), the amplifier will run away. To check the phasing
of the motor and tachometer proceed as follows:
1. Make sure Loop-Gain potentiometer, R18, is full CCW (as shipped from factory).
2. Make sure that nothing is connected to the Signal Input (TB201-3) or the Auxiliary Signal Input (TB201-1
or TB20l-2).
3. Apply the main power and the 120 volt power.
4. Slowly turn the Loop-Gain potentiometer, R18, CW. If the motor starts to run away, turn the Loop-Gain po-
tentiometer full CCW and reverse the tachometer leads (do not move the shield lead). Again, slowly turn
the Loop-Gain potentiometer CW. The motor should be stopped or rotating slowly.
5. Leave the Loop-Gain potentiometer, R18, full CW for all remaining adjustments and operations.
6.4 TACH-GAIN ADJUSTMENT:
1. At this point the motor will be stopped or rotating slowly. Adjust the Balance potentiometer, R15, until the
motor rotation is stopped.
2. While observing the tachometer output voltage with an oscilloscope, apply a step voltage at the Signal In-
CHAPTER SIX: START UP AND ADJUSTMENT PROCEDURE
